This invention relates generally to a cleaning apparatus, and more particularly concerns preventing brush flat spots on a brush by slow rotation.
In an electrophotographic application such as xerography, a charge retentive surface (i.e., photoconductor, photoreceptor or imaging surface) is electrostatically charged, and exposed to a light pattern of an original image to be reproduced to selectively discharge the surface in accordance therewith. The resulting pattern of charged and discharged areas on that surface form an electrostatic charge pattern (an electrostatic latent image) conforming to the original image. The latent image is developed by contacting it with a finely divided electrostatically attractable powder referred to as "toner". Toner is held on the image areas by the electrostatic charge on the surface. Thus, a toner image is produced in conformity with a light image of the original being reproduced. The toner image may then be transferred to a substrate (eg., paper), and the image affixed thereto to form a permanent record of the image to be reproduced. Subsequent to development, excess toner left on the charge retentive surface is cleaned from the surface. The process is well known, and useful for light lens copying from an original, and printing applications from electronically generated or stored originals, where a charge surface may be imagewise discharged in a variety of ways. Ion projection devices where a charge is imagewise deposited on a charge retentive substrate operates similarly.
Although a preponderance of the toner forming the image is transferred to the paper during transfer, some toner invariably remains on the charge retentive surface, it being held thereto by relatively high electrostatic and/or mechanical forces. Additionally, paper fibers, Kaolin and other debris have a tendency to be attracted to the charge retentive surface. It is essential for optimum operation that the toner remaining on the surface be cleaned thoroughly therefrom.
A commercially successful mode of cleaning employed on automatic xerographic devices utilizes a brush with soft conductive fiber bristles or with insulative soft bristles which have suitable triboelectric characteristics.
The following disclosures may be relevant to various aspects of the present invention and may be briefly summarized as follows:
U.S. Pat. No. A-4,490,871 to Martin discloses an apparatus mounted in shower stall including a rotatably mounted brush member that oscillates in a vertical plane or a horizontal plane depending upon the selection chosen by the user of the invention. A set screw having a thumb turn portion to facilitate its manipulation, is provided to act as a brake to slow the rotation of the brush, if desired.
U.S. Pat. No. A-3,818,859 to Kalmar discloses a low volume spray apparatus adapted to apply a mist spray of a high density liquid to the surfaces of fruit and vegetables or the like. The apparatus comprises a rotary brush which is mounted for slow continuous rotation in a position adjacent to the fruit to be sprayed. The coating material is placed in a container which is located so that a peripheral segment of the brush travels therethrough to pick up small quantities of the liquid material on the radially extending bristles.